# NM_005581.5(BCAM):c.691C>T (p.Arg231Ter)

https://sugi.bio/variant/bcam-p-arg231ter

## Summary

**BCAM p.Arg231Ter (c.691C>T)** is classified **Pathogenic** in BCAM (ClinVar, No assertion criteria, 1 submitter; last evaluated 2007-03-01). Very rare (popmax 0.00167%, amr); Associated with BLOOD GROUP--LUTHERAN NULL.

**At a glance:** Pathogenic · review: No assertion criteria · rsID rs121918132 · 1 submitter · 1 linked condition · very rare (popmax 0.00167%, amr)

## For patients & families {#patients}

This is a change in the BCAM gene that is reported as disease-causing, but on limited review, submitted by 1 submitter, and is linked to BLOOD GROUP--LUTHERAN NULL.

*Reference information, not medical advice, and not a prediction for any individual. A genetic counselor or clinician can interpret what it means for you and your family.*

**Support & next steps:** [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [BCAM](https://sugi.bio/atlas/gene/BCAM/) |
| Protein change (HGVS p.) | p.Arg231Ter |
| Coding change (HGVS c.) | c.691C>T |
| MANE Select transcript | [NM_005581](https://www.ncbi.nlm.nih.gov/nuccore/NM_005581) |
| dbSNP | [rs121918132](https://www.ncbi.nlm.nih.gov/snp/rs121918132/) |
| Variant type | single nucleotide variant |
| Location | chr19:44813527-44813527 (GRCh38) |
| ClinVar | [VCV440](https://www.ncbi.nlm.nih.gov/clinvar/variation/440/) |

**All HGVS expressions:** `LRG_798:g.9447C>T`, `LRG_798t2:c.691C>T`, `NC_000019.10:g.44813527C>T`, `NC_000019.9:g.45316784C>T`, `NG_007480.1:g.9447C>T`, `NM_001013257.2:c.691C>T`, `NM_005581.5:c.691C>T`

## Computational & population evidence {#evidence}

**Concordance:** Mixed / partial computational evidence (see below).

- **Missense predictors (AlphaMissense/REVEL/SaProt) do not apply** to this variant type — they score amino-acid substitutions only. For non-missense variants the computational signal comes from conservation (below), not from a missing predictor score.
- Conservation: phyloP 1.217, GERP -0.668, phastCons 0.687 — weakly conserved position
- Molecular consequence: **nonsense (stop-gain)** — a predicted loss-of-function variant. Gene population constraint: LOEUF 1.102, pLI 6.2181e-19. *Descriptive; not an applied PVS1 code.*
- Nonsense-mediated decay: the premature termination codon is **in exon 6 of 15**, so the transcript is predicted to undergo NMD.
- CADD: **PHRED 36.0**. No single ClinGen-calibrated threshold exists and the expert panels that use CADD disagree — GUCY2D/AIPL1 require ≥ 20.0 for an untranslated-region variant, ABCA4 ≥ 28.1 for a synonymous or indel variant, the Pulmonary Hypertension panel imports Pejaver 2022's missense-calibrated numbers, and the Antibody Deficiencies panel declines CADD entirely for PIK3CD. CADD v1.7 also incorporates Zoonomia phyloP, so it partly re-expresses the conservation above. *Descriptive; no threshold applied.*
- SpliceAI: **not assessed** — no allele at this position is in our SpliceAI release, either because it lies outside the scored MANE transcript scope or because every allele is below Δ0.2. We cannot tell which, so this claims neither; absence is not evidence against a splicing effect.
- Population frequency (gnomAD v4.1): grpmax **0.00167%** (amr) · FAF95 0.000183% · FAF99 0.00012% · 1/60,002 in the highest group · 7/1,612,592 alleles overall — very rare (popmax 0.00167%, amr).

| Ancestry group | Allele frequency | 1 in |
| --- | --- | --- |
| Admixed American (grpmax) | 0.00167% | 60,002 |
| European (non-Finnish) | 0.000509% | 196,656 |

*Computational predictors are not independent (ClinGen Variant Classification guidance): AlphaMissense (Cheng et al. 2023) carries the ACMG weight for missense and conservation (phyloP/GERP/phastCons) for non-missense; REVEL (Pejaver-2022 calibrated strength bands) and SaProt (Su et al. 2023, structure-aware, ClinVar-independent protein language model, raw LLR) are shown as orthogonal agreement signals, not additive. For frequency, the gnomAD v4.1 grpmax filtering allele frequency (FAF95) is ClinGen's designated BA1/BS1 input (gnomAD v4 guidance v3.0, June 2025); BA1/BS1 thresholds are disease-specific, not a blanket 5%. Predictions, not a clinical determination.*

## Gene constraint & dosage {#gene-context}

**BCAM** population constraint: LOEUF 1.102, pLI 6.2181e-19, missense-Z -0.54318. *Lower LOEUF and higher pLI indicate a gene that tolerates loss-of-function poorly; ClinGen dosage is the curated haploinsufficiency call.*

## Protein context {#protein}

Residue **231** lies in a disulfide bond; the ig-like v-type 2 domain; an α-helix.

AlphaFold model confidence (whole protein): pLDDT 84.29, 62% of residues very-high.

**2 experimental structure(s)** (PDB): [2PET](https://www.rcsb.org/structure/2PET), [2PF6](https://www.rcsb.org/structure/2PF6).

## What this gene does {#gene-function}

*Describes the biological roles of BCAM (the gene this variant disrupts) — not effects measured for this specific variant. A damaging variant is expected to affect these functions and pathways; the degree depends on the variant.*

**How this variant is thought to act:** BCAM's established molecular role includes laminin receptor activity. p.Arg231Ter falls in the ig-like v-type 2 domain.


### Molecular function & processes (GO — experimentally supported) {#go}

**Molecular function:** laminin receptor activity, laminin binding.

**Biological process:** cell adhesion, cell-matrix adhesion.

## Clinical significance {#significance}

**Pathogenic** — review status No assertion criteria *(no assertion criteria provided)*, last evaluated 2007-03-01.

**Submitter consensus:** unanimous (1/1 Pathogenic).

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| OMIM | Pathogenic | no assertion criteria provided | literature only | 2007-03-01 |

## Associated conditions {#conditions}

[BLOOD GROUP--LUTHERAN NULL](https://sugi.bio/atlas/disease/blood-group-lutheran-null/).

**Reported phenotype names (ClinVar):** BLOOD GROUP--LUTHERAN NULL.

## Similar variants {#similar}

Related BCAM variant pages (same residue, condition, or type): [BCAM p.Arg231Gln](/variant/bcam-p-arg231gln), [BCAM p.Arg231Pro](/variant/bcam-p-arg231pro), [BCAM p.Arg121Ter](/variant/bcam-p-arg121ter), [BCAM p.Cys237Ter](/variant/bcam-p-cys237ter), [BCAM p.Arg282His](/variant/bcam-p-arg282his), [BCAM p.Leu409=](/variant/bcam-p-leu409), [BCAM p.Pro589Leu](/variant/bcam-p-pro589leu), [BCAM p.Thr539Ala](/variant/bcam-p-thr539ala).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-11); gnomAD v4.1 (Broad Institute, built 2026-10-06); AlphaMissense (Cheng et al. 2023, © Google DeepMind — CC BY 4.0, built 2026-01-27); REVEL (Ioannidis et al. 2016 — ODbL, built 2026-07-13); SaProt (Su et al. 2023 — MIT, built 2026-07-14); SpliceAI (Illumina — free for non-commercial use, built 2026-10-13); CADD (Rentzsch et al. 2019, University of Washington — free for non-commercial use, built 2026-10-10); Conservation (phyloP/phastCons/GERP) (UCSC hg38 470-way mammal (Hiller Lab) + Ensembl Compara, built 2026-07-12); gnomAD Non-coding Constraint (Gnocchi) (Chen et al. 2024, Broad Institute — CC0, built 2026-10-11); gnomAD Regional Missense Constraint (Broad Institute — CC0, built 2026-10-13); Pangolin (Zeng & Li 2022 — CC BY 4.0, built 2026-10-11); Repeat regions (UCSC — RepeatMasker, TRF, segmental duplications, built 2026-10-11); ClinGen (ClinGen, built 2026-09-22); UniProt (CC BY 4.0); Reactome / GO (CC BY 4.0, built 2026-09-23); MaveDB (per-record license, built 2026-10-11); CIViC (CC0, built 2026-09-22); Orphanet (Orphanet, built 2026-06-12)

*Primary record: NCBI ClinVar (variation 440). Classifications reflect these databases as of the page's build date and may change. Free reference use — not medical advice; consult the primary submitters and a clinician.*